The present invention relates to a word processor. More particularly, the present invention relates to a word processor having a capability of speedily determining the frequency of use of each word in a text without providing a separate memory.
Word processors have been long known which have a capability of counting a frequency of each word in a prepared, editable text. One such word processor is disclosed in U.S. Pat. No. 4,888,730, which carries out a word frequency count processing to count the frequencies of use of words once a text has been entered and subsequently presents on the display a frequency table, in which processed words are shown in association with their frequencies of use in the text. This prior-art word frequency count processing prevents a text from reading monotonous and immature by overused words.
Such a conventional word processor having a word frequency count capability generally includes a separate word frequency-of-use data memory (hereinafter a frequency data memory) for storing word data in association with a word frequency-of-use data (hereinafter frequency data) in its control unit. While successively reading out words from the first word stored in the text memory, the word processor searches for identical words to those which have already been stored in the frequency data memory. If it encounters a word identical to a previously encountered word, the word processor counts up the frequency of use of the word. For words that appear only once in the text, the word processor stores those words and their frequency data "1" in the frequency data memory.
Furthermore, if all the area of the frequency data memory is used up during a frequency count processing, the frequency count processing is carried out only on the words already stored in the frequency data memory. When a table showing frequencies of use of words in the text (hereinafter a frequency table) is shown or when the frequency table is turned off and the text is shown again, a message such as "WORD FREQUENCY COUNT INCOMPLETE" is shown. The frequency data memory is separately provided, in which a memory capacity of 20-25 bytes is available for the data of each word and the data for 1,000 different words and their frequencies of use can be stored. In this way, long words can be stored in the frequency data memory.
However, the conventional word processor having the above word frequency count capability has the problem that a large capacity frequency data memory is required. Furthermore, the whole word data must be searched through to count the frequencies of use of the words stored in the frequency data memory because the word data is stored in the frequency data memory in the order in which the words are read out from the text memory. This is a remarkably time consuming operation.
If all the available area in the frequency data memory is used up during a frequency count processing, the frequency table applies only to the words stored in the frequency data memory so that the frequencies of use of the words in the entire text cannot be determined. It is impossible to determine at which word the word frequency count processing has been interrupted.